Baltimore Belt Line

B&O's overhead third-rail system at Guilford Avenue in Baltimore, 1901, part of the Baltimore Belt Line. The central position of the overhead conductors was dictated by the many tunnels on the line: the ∩-shaped rails were located at the highest point in the roof to give the most clearance[1]

Connecting the new Philadelphia Branch to the rest of the B&O system was a considerable engineering challenge. A new surface line across the center of town was politically impossible and prohibitively expensive. Building around the outskirts of town would have required massive regrading and bridging, as the terrain is extremely hilly and the line would cut across every watershed flowing into the harbor. As a temporary expedient, traffic was handled through Baltimore on carfloats, but it was clear that a direct connection would have to be built.

The route the B&O chose started from the existing end of track at Camden station, at the west end of the Inner Harbor. A tunnel was constructed directly under Howard Street, heading north until just before it crossed the existing PRR line.

At the north portal of the tunnel, Mount Royal Station was constructed. The track then curved around to the east, passed through six other (much shorter) tunnels, continued across town, finally heading southeast to meet the already constructed line just north of the Canton neighborhood. The cost of construction drove the railroad into bankruptcy shortly after the line opened in 1895.

Initially there were plans to build three new stations, but concern for interference with freight haulage and expense reduced this to a single station at Mount Royal, which opened on September 1, 1896. Lower-level platforms were added at the east end of B&O's Camden Station in 1897.[2][3]

The Howard Street Tunnel, originally a 1.4-mile (2.3 km) long tunnel under Howard Street in downtown Baltimore, took four and a half years to build (1890–95) and was the longest tunnel on the B&O's system.[5] The tunnel is brick-lined with iron-arched centerings. At the time of completion it was considered innovative for its use of electricity for illumination and powering of locomotives. Inside the tunnel, there was an underground platform for trains serving Camden Station. The Howard Street Tunnel is listed on the National Register of Historic Places.[4][6]

Interior of the B&O's powerhouse in 1910, supplying 675 volts DC to the Baltimore Belt Line

By this time the Pennsylvania Railroad line through Baltimore and points south had been in operation for twenty years. Due to the built-up nature of the area traversed and the hilly terrain, much of its line through town was in tunnels, which posed severe ventilation problems. Large chimneys were constructed above the Pennsylvania line, in a not entirely successful attempt to disperse the fumes from the coal-fired locomotives. However, by 1890 electric locomotion was beginning to appear possible, and in 1892 the B&O thus contracted with General Electric (GE) for electric locomotives, powerhouse equipment, and an electrical distribution system.[3] This equipment was delivered beginning in 1895, and the first train pulled by an electric locomotive operated through the Howard Street Tunnel on June 27, 1895.[7]

The grade on the electrified portion was downhill to Camden Station; therefore traffic heading southbound ("westbound", in B&O timetables), from Mount Royal Station, simply drifted through the tunnels. Since the engine was not working, the smoke produced was relatively light. Going upgrade northbound ("eastbound", in B&O timetables) the electric locomotives were coupled to the front of the train at Camden Station and pulled the entire train, including the steam locomotive, through the Howard Street tunnel. When northbound passenger trains stopped at Mt. Royal Station at the north end of the tunnel, the electric locomotive was uncoupled. Northbound freight trains were pulled by electric locomotives for another two miles, until reaching Huntingdon Avenue in east Baltimore. There the steam locomotive closed its cylinder cocks, took up the load, and the electric locomotive uncoupled on the fly, accelerating ahead to a pocket siding between the tracks.[3]

General Electric installed rotary converters in B&O's powerhouse near Mt. Royal Station, having a combined capacity of 5,000 kW to convert 13,200-volt, 3 phase, 25-cycle AC to 675 volts DC. In 1936, these rotary converters were replaced by mercury arc rectifiers.[8]

Initially power was supplied through a unique system in which a pickup shoe rode in a channel above and to one side of the track. This proved vulnerable to contamination from coal smoke, and after a short time it was replaced by a conventional third rail system. When the Howard Street track was made into a gantlet to allow higher clearances, the pickup contacts on one side were mounted on swinging arms to accommodate the varying distance to the third rail. The electrification was finally discontinued in 1952 when dieselization made it unnecessary.[3]

Throughout much of its history until the end of passenger trains in 1958, the line had relatively low passenger traffic, averaging six daily New York–Washington trains each way. Freight traffic was also limited by the scarcity of online industry east of Baltimore and B&O's lack of a connection across the Potomac River at Washington, D. C., to the southern railroads. The massive Pennsylvania main line carried most traffic to the northeast.

By the 1970s, however, both railroads were failing financially. The PRR had been merged into Penn Central in 1968, and two years later the new company declared bankruptcy.[9] The B&O became part of the Chessie System in 1973, which in turn was merged into CSX in 1980.[10]

In 1976 the PRR line became part of the newly formed Amtrak system. The line was subsequently called the Northeast Corridor (NEC), and its role as a freight line became relatively minor. The 1987 accident at Chase, Maryland, involving a Conrail locomotive led to further reductions in freight traffic on the NEC. The Belt Line (now operated by CSX) is therefore a key link in what has now become the principal rail freight line from Baltimore to Philadelphia and beyond. This segment of the CSX network is considered a chokepoint for freight train service from the Port of Baltimore to East Coast and Midwest markets.[11]SeeBaltimore Terminal Subdivision.

On July 18, 2001, a 60-car CSXT freight derailed in the Howard Street Tunnel, sparking a fire that burned for six days and blocked traffic for much longer. The Howard Street Tunnel fire called attention to the Belt Line, both as a risk to the surrounding structures and as a link in rail traffic. CSXT has implemented various improvements to increase the integrity of the link, but is limited by the shallow depth of the bore (only three feet below the surface at the south end) and the instability of the surrounding soil.

On April 30, 2014, a block-long portion of a retaining wall in a below-grade stretch of the Belt Line in southern Charles Village collapsed after a heavy rainstorm, sending part of East 26th Street and a number of cars onto the tracks. No one was injured but the tracks were blocked by debris, shutting down railroad operations as well as the city block directly above them.[12]
On May 2, 2014, freight trains once again began running through the tunnels along this stretch of the Baltimore Belt Line. East 26th Street was reopened to vehicular traffic a year later.

CSX freight train emerging from the north end of the Howard St. tunnel

Reconstructing the Howard Street Tunnel to accommodate double-stacked intermodal containers had been once thought to cost $1–3 billion. However, in April 2016, a $425 million plan was revealed that would create the needed 1.5 ft (0.46 m) of additional clearance in the tunnel by trimming and notching its arched ceiling, lowering its floor, and using steel crossties, which have a lower profile than wood crossties. The Maryland Department of Transportation subsequently applied for a $155 million FY2016 FASTLANE grant to help fund a project based on this lower-cost plan, but the grant was not received. In December 2016, MDOT reapplied for a FASTLANE grant of the same amount in the FY2017 round of funding. In addition to the federal funds expected from the grant, the State of Maryland would contribute $145M, and CSX $125M, towards the cost of the project. In expectation of the grant funding, CSX is investing $25M in the tunnel – $21M to improve its water discharge system, and $4M for engineering and design of the clearance improvements. The project, which would also increase the clearance at nine bridges north of the tunnel, would last 4–5 years (due to having to be scheduled around active rail traffic), create about 500 construction jobs, and would result in 178,000 containers per year being moved by rail from the Port of Baltimore instead of by truck. Maryland Governor Larry Hogan said that the state would explore other funding solutions if the FY2017 FASTLANE grant is not received.[13][14][15][16][17]

^Harwood, Royal Blue Line, p. 86. In the mid-1980s, the tunnel's original length of 1.4 miles or 7,340 feet (2,237 m) was extended an additional three-tenths of a mile (480 m) further south of its original Camden Station portal when the B&O successor CSX Transportation's mainline track east of the B&O warehouse was covered over for construction of Interstate 395 (ref: Stephen J. Salamon, David P. Oroszi, and David P. Ori, Baltimore and Ohio – Reflections of the Capitol Dome. Silver Spring, Md.: Old Line Graphics, 1993 (ISBN1-879314-08-8), pp. 26–28).